Plz check code efficiency

Anon

Hi, I am a newbie (but I am learning fast). I've written tracking code (which goes at the top of my index.php page) that will upload user data into a 5-column mySQL table. Could I please have comments how to either optimize this code, or correct any errors which I have made? thank you!

<?php
$link = mysql_connect('localhost','username','password');
mysql_select_db('database',$link);
$h["ipaddress"] = getenv(REMOTE_ADDR);
$h["iphost"] = gethostbyaddr( $REMOTE_ADDR );
$h["time"] = date("Mj g:ia",time() - 10800);
$h["browser"] = getenv(HTTP_USER_AGENT);
$h["referer"] = getenv(HTTP_REFERER);
foreach(array_keys($h) as $key) {
$k .= ", ".addslashes($key);
if($h[$key] == '') { $h[$key] = "Unknown"; }
$v .= "','".addslashes($h[$key]);
}
$statement = "insert into mytrackinglog ( ".substr($k,2)." ) values ( '".substr($v,3)."' )";
mysql_query($statement,$link);
mysql_close();
?>
<head></head><body></body>

stuartc1

Just one thing - As far as I am aware you cannot be 100% certain that all these Environment variables will be available, this may cause problems in the number of elements in the array. Maybe you should check this before running the SQL.
:->

Anon

Uh oh. How do I do that??? I did the "phpinfo()" thing, and I saw all the stuff that was "turned on," etc., but I don't know what I am looking for.

Maybe this answers your question: The script I wrote DOES work. The visitor's ip address, browser type, referer, etc., DOES get put into my mySQL table.

HOWEVER... I am somewhat worried that my code is not "optimized" or "efficient." Would you please look at my code line by line and please let me know if there is something which is there, but not supposed to be there... or if something is missing...... I get this "feeling" that there is something, "slow" about my code.

Thanks!